The present invention is an improvement to a vertical storage conveyor type apparatus which has been sold and used for parking or storing a number of different items, such as automobiles and automotive parts. Such apparatuses have been sold more than a year prior to the filing of this application and are generally described in the following U.S. patents by the same inventor as herein: U.S. Pat. Nos. 3,424,321; 3,547,281; and 3,656,608, the entire disclosure of each of which is incorporated herein by reference. While there are many features of the present invention in common with this prior art, which such features are described in the aforementioned patents and some of which will be noted hereinbelow in this specification, differences between the present invention and the prior art exist in the power and drive mechanisms.
These prior art vertical conveyors employ two independent vertical frames that are supportingly connected together by beams and struts. Each vertical frame contains an independent conveyor assembly, substantially depicted in the aforementioned U.S. Pat. No. 3,547,281, and which separately convey one end of a load carrying pan. Each conveyor assembly is comprised of a plurality of rigid, compression links pivotally connected together with joint pins to form an endless vertical chain. Suspended from the compression links are a number of pans or platforms arranged in two parallel vertical columns. Rollers or wheels are mounted at each end of the link joint pin travel and are constrained to move only within a vertical guide channel.
A power or motor means, comprised of a single motor mounted on one of the vertical frames, utilizes a conventional electrically driven hydraulic pump to operate a primary drive means located on that frame and through a transmission shaft a primary drive means located on the other frame. Each primary drive means, which is substantially similar to that disclosed in U.S. Pat. No. 3,547,281, includes a number of reduction gear chains reversibly driven by the motor means, which in turn reversibly rotate a lower drive sprocket. The lower drive sprocket in turn drives a gear chain mounted on that sprocket and an upper idler sprocket. Attached to the gear chain are a plurality of fish-shaped pickup members journalled in a spaced apart generally upright, but slightly pivotal relationship. The pickup members engage a compression link joint pin such that when the gear chain is rotated by the motor means, the rotating pickup members, guided by a stationary cam surface, sequentially engage the joint pins to lift that side of the compression links. A tension idler gear removes the slack in the non-driven side of the gear chain.
Although a vertical conveyor according to the aforedescribed prior art functions satisfactorily, it still has a number of drawbacks. For example, the prior art vertical conveyor utilizes an electrohydraulic drive means that includes an electrical motor driving a hydraulic pump which in turn drives a hydraulic motor. While hydraulic drives tend to be reliable, they still require a lot more maintenance, they are relatively noisy and uneven in operation, and they are messier. They also must be kept clean and free of foreign matter which could greatly interfere with a hydraulic motor's operation. In addition, the size of a hydraulic motor and its need for oil sumps, filters, etc. make them heavier, overall more expensive and demanding on the layout and structural design of the supporting frame. Furthermore, it is desirable to have a conveyor system that can be easily assembled and disassembled and moved. A hydraulic drive system is not that easy to install or to remove and move.
Thus, it would be advantageous to be able to utilize other types of power systems, such as one that only uses an electrical motor.
In a vertical conveyor of the type described, the basic loading parameters and the structure of conveyor frame are highly interrelated. One of the principal advantages of this type of vertical conveyor which permits a greater loading, yet still permits the frame weight to be minimized, is the location of the motor means and the conveyor drive means. They are located in the lower vertical half of the device, contrary to a device manufactured by numerous Japanese companies in which they are located near the top of the conveyor. A lower placement greatly reduces the overall conveyor weight, reduces the strength requirements, and provides easier maintenance.
It is also desirable to keep the overall footprint of the conveyor as small as possible. In the prior art device, the footprint is only the area of two automobile parking spaces. However, this devise could only carry twenty-two automobiles. If it is desired to maintain this two-car footprint, yet also to increase the number of automobiles that can be held to, for example, thirty-two or even fifty, the weight distribution and frame structure and size must be carefully designed. Also, the power of the motor means must be considered in order to accommodate the increased number of automobiles. In addition, generally speaking, the more powerful the motor for driving the conveyor, the larger are its physical dimensions. All of the foregoing must be considered in designing a simpler, lighter, and more economical motor and drive system.